Add tests for cvref

Author: cor3ntin

clang/lib/Sema/SemaDeclCXX.cpp

@@ -1665,6 +1665,12 @@ std::optional<unsigned> Sema::GetDecompositionElementCount(QualType T,
                                                            SourceLocation Loc) {
   const ASTContext &Ctx = getASTContext();
   assert(!T->isDependentType());
+
+  Qualifiers Quals;
+  QualType Unqual = Context.getUnqualifiedArrayType(T, Quals);
+  Quals.removeCVRQualifiers();
+  T = Context.getQualifiedType(Unqual, Quals);
+
   if (auto *CAT = Ctx.getAsConstantArrayType(T))
     return CAT->getSize().getZExtValue();
   if (auto *VT = T->getAs<VectorType>())

clang/test/SemaCXX/builtin-structured-binding-size.cpp

@@ -74,7 +74,11 @@ static_assert(__builtin_structured_binding_size(P1) == 0);
 
 
 static_assert(is_destructurable<S0>);
+static_assert(is_destructurable<const S0>);
+static_assert(is_destructurable<volatile S0>);
+static_assert(!is_destructurable<S0&>);
 static_assert(is_destructurable<S1>);
+static_assert(!is_destructurable<S1&>);
 static_assert(!is_destructurable<SE1>);
 static_assert(!is_destructurable<int>);
 static_assert(!is_destructurable<int[]>);
@@ -121,6 +125,12 @@ struct tuple_size<TSizeError> {
 };
 
 static_assert(__builtin_structured_binding_size(T0) == 0);
+
+static_assert(is_destructurable<const T0>);
+static_assert(is_destructurable<volatile T0>);
+static_assert(!is_destructurable<T0&>);
+
+
 static_assert(__builtin_structured_binding_size(T1) == 1);
 static_assert(__builtin_structured_binding_size(T42) == 42);
 static_assert(__builtin_structured_binding_size(TSizeError) == 42);